Body Fat Calculator
Two methods, one honest number. The US Navy tape method reads your neck and waist; a weight-based formula adds your body weight, so lifters with more muscle aren't overestimated. You also get your lean mass and metabolism.
| US Navy (neck + waist) | — |
| Weight-based (YMCA) | — |
| Lean mass | — |
| Metabolism at rest (BMR) | — |
Why two methods?
The US Navy formula only looks at your neck, waist and height. That works well for average people, but it can't see how heavy you are, so a muscular lifter and an untrained person with the same waist get the same number. The YMCA formula uses your weight and waist: at the same waist, more body weight means more lean mass and a lower body fat. Averaging both cancels a lot of each method's error.
Your BMR uses the Katch-McArdle formula, which is based on lean mass, so it fits people who train better than formulas based on total weight.
Body fat categories
| Category | Men | Women |
|---|---|---|
| Contest shape | 4 – 6% | 10 – 13% |
| Athletic | 6 – 13% | 14 – 20% |
| Fit | 14 – 17% | 21 – 24% |
| Average | 18 – 24% | 25 – 31% |
| Above average | 25%+ | 32%+ |
Formulas can still be off by 3–4%
Send 4 photos and get your body fat range, your insertions and your FFMI analyzed, plus whether to bulk, cut or recomp.
Get my Genetics Report: $29.99Formulas: Hodgdon & Beckett (US Navy, 1984); YMCA / Covert Bailey waist-weight equation; Katch-McArdle BMR. Educational estimates, not a medical assessment.
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